eagerly waiting for it man..
keep up this great work

Just want to share my experience with new kind of SDC

Anyone looking for SDC unpacker probably someone like
me who have official MSDN-AA downloader. I don’t know
how the official downloader behave in the past, some
said that it sometimes fail/refuse to resume download,
but for me the main problem is that it’s very slow.
That’s why I am using the alternative download location
like http://oknos.fi.muni.cz, ftp://ftp.sh.cvut.cz or
any other sources since the beginning and never use the
official downloader to download a complete SDC file.

Before, this alternative way was problem free for me,
I could just download the SDC files I want and then
decrypt it using unpacksdc.exe or manually using XOR.
But it seems there are certain (new) SDC that has new
encryption like the one mentioned many times above:
en_windows_7_professional_x86_dvd_x15-65804, which is
splitted into TWO files. This new kind of SDC file
can’t be decrypted using the previous method. Using
file(1) utility in Linux the file detected as ACB
file. Some site describe it as AOL CAB Launcher.

So I tried to put these two files:
en_windows_7_professional_x86_dvd_x15-65804.01.sdc
(2.147.483.647 bytes)
and
en_windows_7_professional_x86_dvd_x15-65804.02.sdc
(217.751.301 bytes)
in the same directory as the official downloader
expecting the files would be unpacked by it. But as
you might guess, it fail to unpack with SD00400 error
message.

After a couple trial-and-error I found that the
offical downloader expects the file that you want
to resume/unpack must be multiplication of a certain
size. I DON’T KNOW THE NUMBER, but I know that
number when multiplied by any integer will result as
a number which is ended by double zeros like 51.200
bytes, 153.702.400 bytes, etc.

Try to download the right way using the official
downloader in another EMPTY DIRECTORY and close it
in the middle of the download, and then take a look
the downloaded SDC file size, the size will be the
size that the official downloader expect. The
smallest I got is 51.200 bytes, so I will use this
number troughout this post.

Now, all you have to do is to truncate the file you
want to resume/unpack so the file size is a
multiplication of 51.200 bytes. In my case I want
to resume:
en_windows_7_professional_x86_dvd_x15-65804.01.sdc
(2.147.483.647 bytes)
and did this math:
2.147.483.647 / 51.200 = 41.943 (rounded)
51.200 * 41.943 = 2.147.481.600

So, I reduce the file size to 2.147.481.600 bytes
by removing a few kilobytes using a hex editor or
dd if you are using UNIX(-like) OS. Now put this
truncated file in the same directory as the
official downloader, run it, click resume, and the
official downloader should resume the download and
unpack it. The final SDC will be a single file
tough (same name as the first file). I assume the
second file appended automatically by the
downloader.

After unpacking the final ISO file is smaller than
both downloaded file combined, whic is 2.200.927.371
bytes. SHA1 checksum is:
CAD5E0C8B5A852BAA83E9CCFB70542A73B6178A9
different from the one that I know from various
sites, which is:
697FA06554502FB21D30275273B25747299C020D

That’s it for now, I hope someone find a better
way. I will try to install from this ISO and I hope
everything will be fine (everything looks okay
inside the installer).

So, I don’t exactly understand how the unpacker works? Do I need Visual Studio? Cause I”m definitely having the same problem with the new Windows 7 Pro x64… it stops right before it starts unpacking… at the “checking CRC.” Could someone give me step by step directions? That would be great!